The sum of the first n terms of an AP is given by
Sn =n/2{2a + (n-1)d}
where a= 1st term, d= common difference
236 = 8/2{2a +(8-1)d} ==>2a + 7d =59....(i)
and
147 = 6/2{2a + (6-1)d} ==>2a + 5d = 59...(ii)
eqn (i) - eqn (ii)==>2d = 10
==> d= 5
Githiari answered the question on April 3, 2019 at 17:28
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